Field
Aspects of the present disclosure relate generally to thermoform manufacturing, and more particularly, to thermoforming with precision in-lay.
Background
Thermoforming is a manufacturing process that uses thermoplastic flat sheets or film to create molded 3 dimensional plastic items. The sheet or film is usually heated to its forming temperature by using various heating mechanisms, such as infrared, natural gas, or the like. The heated plastic is then stretched over or into a mold. The mold may often be temperature-controlled and may provide only single-surface. The plastic is held against the mold surface unit until cooled. Various methods for holding the plastic are commonly used, such as by using a vacuum (vacuum molding), or a combination of a vacuum and compressed air (pressure molding). Once the plastic has cooled sufficiently, the formed part is removed from the mold and may then be trimmed from the sheet, which may then be reground, mixed with virgin plastic, and reprocessed into another usable sheet.
In various thermoform-manufactured products, decorative applications may be made to the formed part. Traditionally, such cosmetic additions have been made through screen printing or painting. In screen printing, an application of colored ink is made over the formed plastic component to produce the desired design, whether for cosmetic, decorative, or identification purposes. Alternatively, a direct spray of paint may also be applied directly to the formed product in order to produce these visual results.
While screen printing or painting produce good results in transforming the plain, molded part into a commercial unit, because of the surface coating nature of these applications, the applied designs will generally wear off as the part is cleaned or handled or impacted. The rate of wear will depend on the particular solvents used for cleaning or the degree to which the item is impacted or abraded. Therefore, the appearance of the part may become unsatisfactory before the end of the useful life of the product.
One solution that has been used to address excessive wear in screen printed or painted formed parts is in-laying. The in-laying process replaces the ink or paint with a thin film of plastic that is embedded directly into the plastic substrate outer surface of the object during the thermoforming process. Various colors and design of such plastic film embedded into the underlying plastic of the formed part create favorable cosmetic, decorative, or identification results. Moreover, because the design is made from embedded plastic film, the design will generally be impervious to the typical wear and tear associated with screen printing or painting.